Steam trap

ABSTRACT

A steam trap to be utilized on exit tubing from steam appliances to permit return of condensed water to a boiler while simultaneously preventing return of pressurized steam. The trap comprises a sealed holding tank having a steam pipe leading from the appliance into the tank, and an upright standpipe extending vertically into the tank. The lower end of the standpipe includes a bottom opening through which the water condensate is free to pass. The upper end of the standpipe includes an electrode that is situated within the standpipe adjacent the top of the tank. A portion of the standpipe extends vertically above the top of the holding tank and is connected to a drainpipe. The pipe includes a solenoid-operated valve connected in an electrical circuit with the electrode. The electrode is located within the standpipe so that buildup of condensate within the holding tank must reach a certain level before the electrode is engaged by the accumulating condensate. Once engaged, the circuit is completed and the solenoid valve is actuated to open, allowing the condensate within the holding tank to be forced vertically through the standpipe and out the drainpipe. As the tank empties, the condensate leaves engagement with the electrode and the circuit is broken. This releases the solenoid valve and the pressurized steam is prevented from leaving the confines of the holding tank.

United States Patent [451 Sept. 16, 1975 Green 1 STEAM TRAP [76]Inventor: Edwin Laurence Green, P.O. Box

1127, Twin Falls, Idaho 83301 [22] Filed: Apr. 29, 1974 Appl. No.:465,090

Primary ExaminerAlan Cohan Attorney, Agent, or Firm-Wells, St. John &Roberts [57] ABSTRACT A steam trap to be utilized on exit tubing fromsteam appliances to permit return of condensed water to a boiler whilesimultaneously preventing return of pressurized steam. The trapcomprises a sealed holding tank having a steam pipe leading from theappliance into the tank, and an upright standpipe extending verticallyinto the tank. The lower end of the standpipe includes a bottom openingthrough which the water condensate is free to pass. The upper end of thestandpipe includes an electrode that is situated within the standpipeadjacent the top of the tank. A portion of the standpipe extendsvertically above the top of the holding tank and is connected to adrainpipe. The pipe includes a solenoid-operated valve connected in anelectrical circuit with the electrode. The electrode is located withinthe standpipe so that buildup of condensate within the holding tank mustreach a certain level before the electrode is engaged by theaccumulating condensate. Once engaged, the circuit is completed and thesolenoid valve is actuated to open, allowing the condensate within theholding tank to be forced vertically through the standpipe and out thedrainpipe. As the tank empties, the condensate leaves engagement withthe electrode and the circuit is broken. This releases the solenoidvalve and the pressurized steam is prevented from leaving the confinesof the holding tank.

2 Claims, 1 Drawing Figure L9 ,r/f

STEAM TRAP BACKGROUND OF THE INVENTION The present invention is relatedto steam systems and more particularly condensing to mechanisms forrecovering water condensate from steam systems. Such apparatus iscommonly associated with steam appliances such as those used in drycleaning operations. In such systems, a steam trap is required to enablereturn of condensed water to a boiler without permitting return ofpressurized steam.

Most conventional steam traps utilize a mechanical float that operates aflap valve or small disc that raises in response to condensate levelwithin a holding tank. Most conventional steam traps have very smallexit orifices that prevent quick release of the collected condensate.Further, most of these devices permit steam to escape along with thecondensate each time the trap opens. This is undesirable since steampressure is sacrificed along with the heat value of the escaped steam.

A United States patent granted to Williams US. Pat. No. 2,368,509discloses a water control discharge with an electrode contacted bycollected water to operate a valve. The valve permits discharge of thecollected water under steam pressure. The arrangement does not includean upright standpipe to assure discharge of a comparatively large volumeof water under steam pressure and appears incapable of differentiatingbetween escaping water condensate and steam exiting from the tank andassociated steam system.

The apparatus of the present invention comprises a sealed holding tankconnected to the steam system and having an upright standpipe extendingdownwardly into the holding tank to a bottom end adjacent the bottom ofthe holding tank. An upper end of this standpipe extends verticallyoutward from the holding tank and includes a drainpipe fixed thereto.The drainpipe includes a solenoid-operated valve that is connected incircuit to an electrode mounted within the standpipe and having anexposed tip adjacent to the top of the holding tank. As condensatereaches the level within the holding tank, the exposed electrode tip isengaged and a circuit completed to operate the solenoid valve to openthe drainpipe and allow steam pressure to evacuate the holding tank ofthe water condensate. Once the exiting condensate leaves engagement withthe exposed electrode tip, the solenoid valve automatically closes,preventing escape of steam from the holding tank and the steam system.

SUMMARY OF THE INVENTION A steam trap is disclosed for separatingpressurized steam from water condensate. The steam trap comprises anenclosed holding tank for receiving pressurized steam and watercondensate from a steam pipe leading into the tank. An upright standpipeextends into the tank and includes a bottom opening adjacent the bottomof the tank and an upper end extending outwardly from the top of thetank. Sensing means is located within the standpipe adjacent the upperend thereof for sensing a prescribed level of condensate within thestandpipe. A drainpipe openly communicates with the upper end of thestandpipe and includes a valve means mounted thereon responsive to thesensing means for opening the drainpipe as the condensate reaches saidprescribed level and closing the drainpipe when said condensate is fullor not engaging the sensing means. The condensate is therebyautomatically drained by force of said pressurized steam to the level ofthe bottom opening of the standpipe.

It is a first object of my invention to provide a steam trap foreffectively allowing evacuation of water condensate from a steam systemwithout allowing accompanied escape of pressurized steam.

It is another object to provide such a steam trap that will facilitateevacuation of substantially large amounts of condensate from a steamsystem in a relatively short period of time.

It is an additional object to provide such a steam trap that is veryeconomical to utilize in conjunction with present steam systems.

A yet further object is to provide such a steam trap that is simple inconstruction and substantially maintenance free.

These and other objects and advantages will become apparent upon readingthe following disclosure which, taken with the accompanying drawing,disclose a preferred form of my invention.

BRIEF DESCRIPTION OF THE DRAWING A preferred form of the presentinvention is illustrated in the accompanying drawing which is asubstantially diagrammatic representation of a longitudinal crosssection of my invention and associated circuitry.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to thedrawing in greater detail, a preferred form of my invention is shownbasically comprising a holding tank 10, a steam pipe 11 leading into theholding tank 10, an upright standpipe 18 and an attached drainpipe 30leading from the holding tank. A sensing means 23 is positioned withinthe standpipe l8 and is connected by a normally open electric circuit 35to a valve means 31. The sensing means 23 and valve means 31 areoperative to detect a prescribed level of water condensate within theholding tank 10 and to allow the condensate to be drained from theholding tank under pressure from steam entering through pipe 11..

The holding tank 10 is comprised of a sealed container formed with abottom wall 13, a top wall 14, side walls 19 and end walls 15. The steampipe 11 openly communicates with the hollow interior of tank 10 byconnection through one of the end walls 15. The steam pipe 11 may be anintegral portion of a steam system such as those commonly utilized in adry cleaning operation. The attached steam system is not shown in theaccompanying drawing. It may be understood however that steam and watercondensate are directed under pressure from the steam system through thesteam pipe 11 and into the holding tank 10.

The standpipe 18 is located adjacent the end 15 opposite that connectedto the steampipe 11. Standpipe 18 is upright and extends vertically intothe tank 10, leading downward to a bottom opening 20 adjacent tankbottom wall 13. Standpipe 18 further includes an upper end 21 thatextends upwardly and outwardly from the top wall 14 of holding tank 10.Standpipe 18 may be provided as an integral element of the holding tank10, as illustrated, or may be threadably engaged or otherwise attachedto the holding tank in a position as illustrated in the drawing. Thedrainpipe 30 is similarlybonnected to the upper end 21 of standpipe 18to openly communicate with the hollow interior thereof. Thus, anycondensate evacuated from holding tank must first move upwardly fromopen end to the drainpipe 30. The level of opening 20 thereby determinesthe level of condensate after the evacuation process.

The sensing means 23 is basically comprised of an electrode 24 mountedwithin the upper end of standpipe 18 and extending downwardly into theholding tank 10. The electrode 24 is partially encased by an insulator26 so that only a small portion or tip is exposed within the holdingtank 10. Sensing means 23 is attached to the standpipe 18 by means of athreaded plug 27 engaged within the otherwise open top end 21 ofstandpipe 18. Electrode tip 25 defines a prescribed level at which thecondensate is allowed to reach before the valve means 31 is operated torelease the condensate through drainpipe 30 under steam pressure.

Valve means 31 may be comprised of a conventional valve plunger 32mounted to a solenoid 33. The plunger 32 is vertically movable betweenan open position wherein a passage is opened to allow free movement ofthe condensate through drainpipe 30, and a normally closed position(illustrated in the drawing) maintained by a compression spring 34.

Solenoid 33 is operated by sensing means 23 and a power means 37 in theform of a battery or other power source connected in the circuit 35.Solenoid 33 is insulated to prevent electrical contact with drainpipe30. Therefore, connection is made to the power means 37 and sensingmeans 23 solely through means of connecting wires.

A first wire 38 extends from solenoid 33 to the electrode 24, and asecond wire 40 extends from the solenoid 33 to power means 37. Theholding tank 10 and pipes connected thereto are utilized by the circuitas a common ground. It may be noted in the drawing that valve means 31is normally closed since the solenoid 33 and sensing means 23 are bothinsulated from the com mon ground. The circuit to valve means 31 iscompleted, however, once the water condensate reaches the level ofexposed electrode tip 25. When this occurs, the condensate becomes aconductor and solenoid 33 is operated to move plunger 32 to the openposition, allowing condensate to be forced by steam pressure throughdrainpipe 20.

The condensate will continue to be forced by steam pressure from theholding tank so long as it remains a conductor between electrode tip 25and ground. Further, the position of bottom opening 20 of standpipe 18facilitates removal of almost all of the condensate within holding tank10 since it is located adjacent the bottom wall 13. The condensate mustdrain to a level below the bottom opening 20 before steam is allowed toenter the standpipe 18.

Any steam or air existing within the tank, before the condensate levelbegins to rise, is exhausted through a small escape aperture 36 locatedadjacent the top wall 14 of tank 10. The escape aperture 36 extendsthrough the standpipe and openly communicates between the hollowinterior of the standpipe and the interior of holding tank 10. Any airwithin standpipe 18 is thereby forced into the holding tank 10 as thecondensate 12 rises.

It may be understood that the escape of steam from the holding tank 10is prevented at the instant the condensate leaves engagement with theexposed electrode tip 25. As the condensate disengages tip 25, thecircuit 35 is again opened and solenoid 33 is deactivated, allowingcompression spring 34 to return plunger 32 to the closed position. Thisstep is accomplished almost instantaneously so that no steam is allowedto escape the holding tank or associated steam system.

On occasion the device is temporarily disabled by an air lock withintank 10. This can be remedied by adding an air vent 42 open to theinterior of tank 10. The air vent 42 is a pressure-operated valve,normally closed. It is pre-set to open at a pressure slightly greaterthan the operating steam pressure. If air in the tank 10 is compressed,vent 42 will open and allow the air (and steam) to escape momentarily,thereby making room for incoming condensate. Alternately, a small airline (not shown) running to the high point of the pipe 11 can also beused to bleed trapped air within tank 11.

It may have become apparent from the above description and attacheddrawings that various modifications may be made therein withoutdeparting from the intended scope of this invention. It is for thisreason that only the following claims are to be taken as definitions ofmy invention.

What I claim is:

l. A steam trap for separating pressurized steam from water condensatecomprising:

an enclosed holding tank for receiving pressurized steam and watercondensate from a steam pipe leading into the tank,

an upright standpipe extending into the tank and having a bottom openingadjacent the bottom of the tank;

sensing means within the standpipe and elevationally located within thetank for sensing presence of condensate at a prescribed level within thestandpipe and tank;

a drainpipe openly communicating with said standpipe at a locationelevationally above said prescribed level;

a relief aperture formed through said standpipe elevationally above saidprescribed level for allowing escape of gas from within said standpipeas condensate raises therein:

valve means mounted on said standpipe for opening the drainpipe andclosing said drainpipe; and

power supply means operatively interconnecting said sensing means andsaid valve means responsive to said sensing means for actuating saidvalve means to open said drainpipe as said condensate reaches saidprescribed level and engages .said sensing means, and to actuate saidvalve means to close said drainpipe when said condensate passes beyondthe sensing means and becomes disengaged with said sensing means.

2. The invention set out in claim 1 wherein said power supply means iscomprised of an electrical circuit with a source of electrical energy;and

wherein said sensing means comprises an electrode, connected to saidelectrical circuit and electrically insulated from said standpipe andtank and having an exposed tip at said prescribed condensate level; and

wherein said valve means includes a solenoid operated valve connected insaid circuit to said source of electrical energy and to said electrode,said source of electrical energy being connected in said circuit to saidcondensate, whereby engagement of said condensate with said electrodecompletes said circuit and disengagement of said electrode andcondensate opens said circuit to thereby operate said solenoid operatedvalve to open and close said drainpipe.

1. A steam trap for separating pressurized steam from water condensatecomprising: an enclosed holding tank for receiving pressurized steam andwater condensate from a steam pipe leading into the tank, an uprightstandpipe extending into the tank and having a bottom opening adjacentthe bottom of the tank; sensing means within the standpipe andelevationally located within the tank for sensing presence of condensateat a prescribed level within the standpipe and tank; a drainpipe openlycommunicating with said standpipe at a location elevationally above saidprescribed level; a relief aperture formed through said standpipeelevationally above said prescribed level for allowing escape of gasfrom within said standpipe as condensate raises therein: valve meansmounted on said standpipe for opening the drainpipe and closing saiddrainpipe; and power supply means operatively interconnecting saidsensing means and said valve means responsive to said sensing means foractuating said valve means to open said drainpipe as said condensatereaches said prescribed level and engages said sensing means, and toactuate said valve means to close said drainpipe when said condensatepasses beyond the sensing means and becomes disengaged with said sensingmeans.
 2. The invention set out in claim 1 wherein said power supplymeans is comprised of an electrical circuit with a source of electricalenergy; and wherein said sensing means comprises an electrode, connectedto said electrical circuit and electrically insulated from saidstandpipe and tank and having an exposed tip at said prescribedcondensate level; and wherein said valve means includes a solenoidoperated valve connected in said circuit to said source of electricalenergy and to said electrode, said source of electrical energy beingconnected in said circuit to said condensate, whereby engagement of saidcondensate with said electrode completes said circuit and disengagementof said electrode and condensate opens said circuit to thereby operatesaid solenoid operated valve to open and close said drainpipe.